In an information-oriented society these days, the role of an electronic display is getting more important. All kinds of electronic displays are widely used in various industrial fields. As techniques of the electronic display field are continuously developed, various electronic displays having new functions are provided corresponding to diverse requirements of the information-oriented society.
Generally, electronic display is an apparatus for visually transmitting information to a person. That is, electronic display can be defined as an electronic apparatus, which converts an electrical information signal output from various electronic equipments into a visually recognizable Optical information signal. Also, it may be defined as an electronic apparatus serving as a bridge for connecting the person and the electronic equipments.
These electronic displays are classified into an emissive display in which the optical information signal is displayed by a light-emitting method, and a non-emissive display in which the signal is displayed by an optical modulation method such as light-reflecting, dispersing and interference phenomena, etc. As the emissive display called an active display, for example, there are a CRT (Cathode Ray Tube), a PDP (Plasma display panel), an LED (Light emitting diode) and an ELD (Eelectroluminescesnt Display), etc. And as the non-emissive display called a passive display, there are an LCD (Liquid Crystal Display) and an EPID (Eelectrophoretic Image Display), etc.
The CRT has been used in an image display such as a television and a monitor, etc., over the longest period of time. The CRT has the highest market share in an aspect of displaying quality and economical efficiency, but also has many disadvantages such as heavy weight, large volume and high power consumption.
Meanwhile, as various kinds of electronic devices are small-sized and lighter in weight along with the solidification and lower voltage and lower power driving of the electronic devices due to rapid advancement of semiconductor technologies, there is requested a flat panel type display having slimmer and lighter property as well as lower driving voltage and lower power consumption characteristic according to the new environment.
Among variously developed flat panel type displays, the LCD is much slimmer and lighter than any other displays and it has the lower driving voltage and the lower power consumption. Also, it has the displaying quality similar to that in the CRT. Therefore, the LCD is widely used in various electronic devices. Further, since the LCD can be manufactured with ease, its application is gradually wider.
The liquid crystal display is comprised of two substrates in which electrodes are formed, and liquid crystal interposed there between. The liquid crystal display is a device for performing a displaying operation by applying a voltage to the electrodes, and it realigns molecules of the liquid crystal so as to control an amount of light passing through the liquid crystal.
In these LCDs, a general structure that is being widely used includes two substrates each of which has an electrode formed thereon and a thin film transistor (TFT) for switching a voltage applied to the electrode. Generally, the electrode is formed on either one of the two substrates.
As the resolution of these LCD panels increases, the redundancy of the gate line increases too. The increase in the redundancy of the gate line elevates the possibility in the occurrence of the opening of the gate line, so that the failed pixels may be caused.